With development of a Long Term Evolution (LTE) technology, an overall industry chain of a voice over LTE (VoLTE) from circuit switched fallback (CSFB) to single radio voice call continuity (SRVCC) has been mature, and the VoLTE is widely used.
Compared with a data service of the LTE, a data service of the VoLTE has a higher requirement for LTE radio coverage, and reasons for which mainly include the following aspects:
(1) The VoLTE has a higher requirement for quality of service (QoS) and has a high requirement for real time; therefore, resource scheduling of the LTE needs to preferentially ensure an access rate of the VoLTE;
(2) The VoLTE supports a high-definition voice and video codec, and has a high requirement for bandwidth. Therefore, the resource scheduling of the LTE needs to preferentially ensure bandwidth occupation of the VoLTE.
In a process of studying and practicing the prior art, the inventor of the present invention finds that: because the LTE needs to first ensure a VoLTE requirement is met, when traffic of the VoLTE is extremely heavy, cell congestion occurs, thereby causing a VoLTE-based call failure. In this case, user equipment still continues attempting to initiate the VoLTE call, which exacerbates the cell congestion.